# Body Fat Percentage Question **URL:** \ **Category:** Factual Questions\ **Created:** [June 13, 2003, 4:26pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607 "2003-06-13T16:26:52Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![SandWriter](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@SandWriter](https://boards.straightdope.com/u/SandWriter)\ **Post date:** [June 13, 2003, 4:26pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/1 "2003-06-13T16:26:52Z")
Hey All, The Body Fat Percentage Calipers put me at 20 - 21% body fat. I currently weigh 250 lbs (Down from 300lbs). From that I calculate that I have 52.5 pounds of fat on my body. If I continue to exercise, get down to 200lbs and have a 17% body fat percentage, then I will have 34 lbs of fat on my body. As I’ve lost 50 pounds, but only 28.5 lbs of fat, what was the other 21.5 lbs comprised of? Is it weight lost from my internal organs? I don’t think I will lose muscle as I am performing resistance training at the gym and I’m getting stronger. Thanks, -Sandwriter ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [June 13, 2003, 5:05pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/2 "2003-06-13T17:05:12Z")
Body fat also holds a percentage of sugars and water and/or causes your body to hold onto these things (not sure which part of my statement is correct). Well, more body fat means loosing at least some more sugar, sodium and water in supporting roles. Lose body fat, and those resources go as well. ---
**Author:** ![SandWriter](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@SandWriter](https://boards.straightdope.com/u/SandWriter)\ **Post date:** [June 13, 2003, 5:53pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/3 "2003-06-13T17:53:45Z")
Philster, So what you’re saying is that Fat requires liquid (i.e. heavy) resources, and when you lose the Fat, you no longer need those resources and they go away as well. So if you lose a pound of Fat you actually lose more weight than the Fat by itself. That answer makes sense, but are you Doctor? Do you have any documentation to support that theory? Thanks, -Sandwriter ---
**Author:** ![Boo](https://avatars.discourse-cdn.com/v4/letter/b/7feea3/32.png) [@Boo](https://boards.straightdope.com/u/Boo)\ **Post date:** [June 13, 2003, 7:01pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/4 "2003-06-13T19:01:26Z")
if you are lifting weights and getting stronger, then you are also gaining muscle which is much heavier than fat. So, when you reach 200 pounds, you actually may have much less than 17% body fat. What I’m saying is that the equation is not linear. ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [June 13, 2003, 7:40pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/5 "2003-06-13T19:40:18Z")
Sorry, this was info passed on from ex-trainers. One is a former Mr. USA. ---
**Author:** ![SandWriter](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@SandWriter](https://boards.straightdope.com/u/SandWriter)\ **Post date:** [June 13, 2003, 8:55pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/6 "2003-06-13T20:55:50Z")
Philster - Thanks for citing your source. Boo - Thanks for your response. I tried to take into account the increase in muscle by changing the body fat percentage from 21% to 17%. I agree that muscle is denser than fat. That fact would account for a change in volume. I’m trying to learn what tissue or fluid is lost to compensate for the non-fat weight loss in the example in the OP. Which equation are you referring to as being non-linear? ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [June 13, 2003, 9:01pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/7 "2003-06-13T21:01:49Z")
You can lose muscle and get stronger at the same time. A large part of strength has to do with how much of your muscle your central nervous system will let you use. ---
**Author:** ![j.c](https://avatars.discourse-cdn.com/v4/letter/j/73ab20/32.png) [@j.c](https://boards.straightdope.com/u/j.c)\ **Post date:** [June 17, 2003, 6:41am UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/8 "2003-06-17T06:41:38Z")
Why worry about the details? Why not just be proud of yourself! ---
**Author:** ![etgaw1](https://avatars.discourse-cdn.com/v4/letter/e/ed655f/32.png) [@etgaw1](https://boards.straightdope.com/u/etgaw1)\ **Post date:** [June 17, 2003, 7:24am UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/9 "2003-06-17T07:24:44Z")
Why do you think that when you get down to 200 lbs you will have 17% body fat? ---
**Author:** ![Fuel](https://avatars.discourse-cdn.com/v4/letter/f/df705f/32.png) [@Fuel](https://boards.straightdope.com/u/Fuel)\ **Post date:** [June 17, 2003, 7:34am UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/10 "2003-06-17T07:34:28Z")
You are losing _some_ muscle. Lost muscle is comprising some of the weight loss you are seeing. But not to worry, it’s gonna happen when you lose 100 lbs. You will get stronger, but not from gaining muscle, but from training your central nervous system. Keep up the good work! ---
**Author:** ![SandWriter](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@SandWriter](https://boards.straightdope.com/u/SandWriter)\ **Post date:** [June 17, 2003, 2:54pm UTC](https://boards.straightdope.com/t/body-fat-percentage-question/181607/11 "2003-06-17T14:54:57Z")
j.c., Thanks for the response. I’m worrying about the details cause I worry and/or think about stuff too much, in some people’s opinions. I also believe that if I have a clear understanding of how my body works I will have more control over my weight/body composition. etgaw1, Thanks for the response. I choose 17% for an example. When I was around 300lbs, I was around 26%. At 250lbs I’m around 21%. I extrapolated from there, 200lbs 17%. The actual percentages are not important, what is important to me is to find out what is being lost besides the fat. Fuel, Thanks for the response and the encouragement. Could you elaborate more on the training of the central nervous system?